Total medical care costs of cancers are estimated to be about 5% of national health care expenditures and 10% of Medicare outlays. Accurate measures of medical care costs are important when evaluating cancer interventions, cancer clinical trials, social experiments related to cancer patients, and programs and policies related to cancer prevention, screening, and treatment. This research will take advantage of the HMO Research Network's (HMORN) unique resources to address vital questions related to the manner in which usual care drugs and novel pharmacy-based cancer therapies impact cancer-related health care costs. Specifically we propose the following aims: AIM 1 - We will conduct a survey of leaders of Pharmacy and Therapeutics (P&T) committees, clinical oncology pharmacists, and chief oncologists at the 15 HMORN plans to better understand how policies and guidelines related to the use of new cancer therapies, factors related to the decision-making process for why and when therapies were adopted and/or controlled (e.g., costs, legal claims, scientific evidence, visibility, community standards, patient demands), proportion of patients who refuse cancer therapies due to costs, and issues related to automated data on injection/infused cancer therapies. AIM 2 - Using data from four plans within the HMORN for 2000-2007, we will estimate the effects of variations in benefit coverage and cost sharing (patient out-of-pocket costs) on the total health care costs of cancer overall and for each specific component of care, with a specific emphasis on pharmaceutical costs for all cancer patients and the following specific cancer sites: breast, prostate, lung/bronchus, and colon/rectum cancers. Estimates will be made for all treatment phases (diagnosis/treatment, monitoring, and end-of-life care) for all persons with unique estimates for persons aged 65 and older. Aim 3 - Using HMORN data for 2000-2007 and Medicare Part D claims data for 2006-2007, we will estimate the rates of diffusion of targeted chemotherapy agents, colony-stimulating factors (CSFs), chemopreventive agents, new chemotherapy agents, and novel therapies developed during the past decade among Medicare HMO and FFS enrollees. We will describe the relative costs of these therapies to patients, health plans, and Medicare. AIM 4 - Using HMORN data for 2000-2007, and SEER-Medicare data for 2006-2007, we will model the effects of the increased drug coverage provided by the Medicare Prescription Drug Improvement and Modernization Act of 2003 (Part D) on estimates of cancer-related pharmaceutical services and overall medical care use and costs by cancer site, phase of treatment, and demographic strata (age/race/gender) for Medicare FFS and HMO beneficiaries.